Thanks Boydy, I'll give that a look before trying anything else. Was considering looking at an LED replacement, probably better in the long run.
Thanks to all others for suggestions too.
I agreed to take a look at shop sign for a shopkeeper friend. The fitting apparently stopped working form one day to the next. I have checked the following.
1) 240V getting to the fitting.
2) Both starters work fine in another fitting
3) Buzzed all the way round wiring loop with tubes/starters...
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